Usage
This combination vaccine is indicated for active immunization against diphtheria, tetanus, pertussis (whooping cough), hepatitis B, poliomyelitis (polio), and invasive disease caused by Haemophilus influenzae type b (Hib) in infants and young children. It is crucial to administer this vaccine according to the official recommendations of the relevant health authority.
Pharmacological Classification: Vaccine (Combined). This classification signifies its role as an active immunizing agent.
Mechanism of Action: This combination vaccine stimulates the immune system to produce antibodies against the included toxoids (diphtheria, tetanus, pertussis) and antigens (hepatitis B, filamentous hemagglutinin, pertactin, Hib capsular polysaccharide, and poliovirus types 1, 2, and 3). This generates active immunity, protecting the vaccinated individual against the targeted diseases.
Alternate Names
There is no official international non-proprietary name (INN) for this specific combination vaccine. The name typically used is a description of its components.
Brand Names: Infanrix hexa
How It Works
Pharmacodynamics: This vaccine works by introducing inactivated toxins (toxoids) and antigens into the body. These components mimic the natural infection without causing the actual disease. The immune system recognizes these components as foreign and produces specific antibodies. These antibodies remain in the body, providing long-term protection against future exposure to the pathogens.
Pharmacokinetics: The pharmacokinetic profile of this complex combination vaccine isn’t typically described in traditional terms (absorption, distribution, metabolism, elimination). The individual components are processed differently. For example, the polysaccharide component of Hib is primarily processed by the reticuloendothelial system. Toxoids are processed like proteins. The aluminum salts in the vaccine act as adjuvants to enhance the immune response. The immune response, namely antibody titers, is the key measure of the vaccine’s effectiveness.
Mode of Action: The vaccine components stimulate B lymphocytes to produce antibodies specific to each pathogen’s antigens or toxoids. This immune response provides immunological memory, enabling the body to quickly recognize and neutralize the actual pathogens upon future encounters, thus preventing disease onset.
Dosage
Standard Dosage
Infants: The primary vaccination schedule typically consists of three doses (0.5 mL each), administered at 2, 4, and 6 months of age. A booster dose is recommended later, according to official recommendations.
Side Effects
Common Side Effects
Common side effects at the injection site may include pain, redness, and swelling. Fever, irritability, and loss of appetite can also occur.
Rare but Serious Side Effects
Rarely, more serious side effects such as high fever, persistent crying, allergic reactions, or neurological events have been reported. Immediate medical attention is necessary if such reactions occur.
Contraindications
Contraindications include a history of severe allergic reaction to any component of the vaccine or after a previous dose of a similar vaccine.
Drug Interactions
Immunosuppressant medications may reduce the effectiveness of the vaccine. Concurrent administration with other vaccines is generally well-tolerated, but it is crucial to follow official recommendations regarding the timing and administration of multiple vaccines.
Pregnancy and Breastfeeding
This vaccine is not intended for use in pregnant or breastfeeding individuals.
Drug Profile Summary
- Mechanism of Action: Stimulates antibody production against diphtheria, tetanus, pertussis, hepatitis B, poliomyelitis, and Hib.
- Side Effects: Commonly, injection site reactions and fever. Rarely, severe allergic reactions or neurological events.
- Contraindications: Severe allergic reaction to any vaccine component.
- Drug Interactions: Immunosuppressants.
- Pregnancy & Breastfeeding: Not indicated.
- Dosage: 0.5 mL intramuscularly at 2, 4, and 6 months of age. Booster dose as per recommendations.
- Monitoring Parameters: Observe for any adverse reactions, particularly allergic reactions. Assess antibody titers if indicated.
Popular Combinations
This combination itself is a commonly used formulation for infant immunizations.
Precautions
Standard precautions for vaccinations apply, including screening for contraindications and observing the patient post-vaccination.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for this vaccine?
A: 0.5 mL intramuscularly at 2, 4, and 6 months of age, followed by a booster dose as per local recommendations.
Q2: Can this vaccine be given to premature infants?
A: Yes, the vaccine can be administered to premature infants according to the chronological age, starting at 2 months.
Q3: What should I do if a dose is missed?
A: Consult official immunization guidelines or contact the relevant health authorities for guidance on how to proceed with missed doses.
Q4: Can this vaccine be given with other vaccines?
A: It can generally be administered concomitantly with other childhood vaccines, but consult official recommendations regarding specific combinations and administration schedules.
Q5: What are the common side effects?
A: Common side effects include local reactions at the injection site (pain, redness, swelling) and systemic reactions such as fever, irritability, and decreased appetite.
Q6: What are the contraindications to this vaccine?
A: A history of severe allergic reaction (anaphylaxis) to any component of the vaccine or a previous dose of a similar vaccine is a contraindication.
Q7: How long does the immunity provided by the vaccine last?
A: The duration of immunity varies depending on the specific component. Booster doses are recommended to maintain protection.
Q8: Is it safe to administer this vaccine to immunocompromised infants?
A: The decision to administer this vaccine to immunocompromised infants needs careful consideration by a physician, as the immune response might be reduced. Live vaccine components, like polio, raise particular concerns.
Q9: Are there any precautions regarding storage of the vaccine?
A: Yes, store the vaccine according to the manufacturer’s instructions, typically under refrigeration at the correct temperature. Do not freeze.
